1. Technical Field
The present application relates to determining environmental effects on an oscillator and in particular but not exclusively to determining the deviance of a generated frequency from an ideal due to temperature.
2. Description of the Related Art
Many systems make use of oscillators in order to provide a frequency. In some systems the accuracy of the frequency is important for the correct functioning of the system. One such system is a global navigation satellite system (GNSS).
In order to acquire a received satellite signal, a local signal is generated by a GNSS receiver in order to determine a phase difference with the satellite signal. This phase difference may then be used to determine the position of the receiver with respect to the satellite.
The accuracy of the local signal is important to the functioning of the system. Any frequency error in the locally generated signal leads to an increase in the time taken to acquire the satellite signal as the receiver has to search not only for a phase difference but also potential frequency differences.
Temperature of an oscillator has an effect on the accuracy of the oscillator. The frequency of the oscillator may vary with a change in temperature. In order to address this, many oscillator have built in temperature compensation, for example the temperature controlled crystal oscillator (TXCO), However, such temperature compensation pushes up component price of an oscillator and may increase space required for the oscillator.